Overactive Bladder (OAB): This condition is characterized by a sudden, intense urge to urinate, often accompanied by nocturnal urinary frequency. The absence of dysuria or abdominal pain supports this diagnosis, as OAB typically does not involve pain or discomfort.

Benign Prostatic Hyperplasia (BPH): Enlargement of the prostate gland can cause urinary frequency, urgency, and nocturia in men, especially in the absence of pain or dysuria.
Diabetes Mellitus: Uncontrolled diabetes can lead to polyuria (excessive urine production), resulting in nocturnal urinary frequency and urgency without pain.
Sleep Disorders: Certain sleep disorders, such as sleep apnea or insomnia, can increase the likelihood of waking up to use the bathroom, contributing to nocturnal urinary frequency.
Fluid Intake: Excessive fluid consumption, especially before bedtime, can lead to nocturnal urinary frequency.

Diabetic Ketoacidosis (DKA): Although less likely, DKA is a life-threatening condition that can present with polyuria and should be considered, especially in patients with a history of diabetes.
Urinary Tract Infection (UTI) without Typical Symptoms: In some cases, UTIs can present without the typical symptoms of dysuria or abdominal pain, especially in older adults or those with compromised immune systems.
Bladder Cancer: Although rare, bladder cancer can cause urinary frequency and urgency, and it is essential to rule out this diagnosis, especially in patients with risk factors such as smoking.

Interstitial Cystitis: A chronic condition causing bladder pressure, pain, and sometimes urinary frequency, although pain is a more typical symptom.
Neurogenic Bladder: A condition resulting from nerve damage affecting bladder function, which can lead to urinary frequency and urgency.
Pituitary Tumors: Certain pituitary tumors, such as those producing ADH, can lead to changes in urine production and nocturnal urinary frequency.